Project Summary/Abstract Nearly 300,000 Americans have sustained some form of spinal cord injury (SCI), and effective therapies to promote recovery of neural function are lacking. Our overarching vision is to create an ex-vivo tissue that can replace the damaged spinal cord and enable formation of new relay circuits across sites of even severe injury. Our extensive rodent work with 3D printed biomimetic scaffolds shows that this approach can result in electrophysiological and functional recovery after complete spinal cord transection, the most severe model of spinal cord injury. This project aims to assess the efficacy of 3D printed biomimetic scaffolds, loaded with human neural progenitor cells and implanted acutely, in a long-term clinically relevant, non-human primate model of cervical spinal cord contusion. There are 2 objectives to this project: 1. Analysis of anatomical outcomes - Biocompatibility, integration, degradation, vascularization, host axon regeneration into the scaffold, and neural progenitor cell-derived axon outgrowth from the scaffold into the host. 2. Analysis of functional outcomes. Animals will be functionally assessed on tasks of right- hand function, including Brinkman board, home cage-based robotic manipulation, forelimb and hindlimb use in an open field/exercise enclosure, and sensation. Successful performance outcomes of the grant may lead to clinical trials, with resulting high impact.